Rheostat.



YNfIED STATE Y L QGEPGRATION 0F the appfmd cfm,

Referring tu the :wml: and if; the Various vis-*Ws 351i? Limi,

Applicatien EL .sda which is simpe am en sf the inverz im vssentia chamctersia a rheostat demoni flmbmying he principlesA of mymveni mi ffmuprises a sflrif-s ui' metallic ffl! xgmn vauh father, the Sueco OF UH WEST il i i iii!" i Y 'g2g Patent Y Sgm 1%. 255,4@

S PATENT OFMQE.

Ylf, ASSIH )IGR T? CHCAGO,

a surcient nun gia @r mln legs o? the as mest' death tact of the sections A where they rest upon each other in the pile. It will also be seen that the bolt B is entirely out of contact with any of the sections composing thc rheostat elementf It will also be seen that I provide an o en construction permitting of the tree circu ation of air, and hence presenting a wide radiation area, ermitting the dissipation and radiation ofpauy heat that may he generated while the rheostat is in use, and this is a valuable feature of my invention.

While I have shown a rheostat element built up of superposcd U-shaped n1etallicsections A, of wire or other suitable form in Fig. 3, I do not desire to be limited or restricted to `:this arrangement. For instance, in Fig. 6 I have indicated a forni in which the rheostat element is built up of short straight metallic sections K, which may be of wire and piled upon each other after the fashion of a log house. In Fig. 4 I have shown a form wherein the metallic sections Ii are of triangular shape, the triangles being piled in crosswise or inverted relation the one upon the other to form the rheostat element, and in Fig. 5 I have shown the sections M in the form of rectangles designed to be iled in crosswise relation the one upon t e other to form the rheostat element. The form shown in- Fig. 3 I have found preferable, however, be cause since the resistance of the element is dependent upon the number of contacts be tween the sections composing the element the arrangement shown in Fig. 3 presents the fewest number of such contacts-vnamely, fourwbetween adjacent sections A, whereas in Fig. si)r contacts are presented between adjacent sections L, and in Fig. 5 eight contacts arc made between adjacent sections M. In Fig. 6 the same number of contacts be tween the strips or sections K is presented as in the case of Fig. 3; but the assembling of the sections K requires more careful handling than in the case of the U-shaped sections of Fig. 3. However, I have found all of the illustrated forms suitable for my purpose, and therefore do not desire to be limited or rcstricted to any specific arrangement of the sections composing the resistance element.

One or an number of rheostat elements may be employed to form theI rheostat, uccording to the requirements. Where one element is used alone, the circuitterminals are connected to the terminal plates l" at the respective ends of the element Where two or more elements are associated to form the rhcostat, the terminal plate l" at thc respective ends of each element is electrically connected to the terminal plate at thc corresponding ends of adjacent elements on opposite sides thereof in a well-umlerstood manner. ln Fig, l l have shown n. rhcostat cml ploying three elements, thc terminal plate at i one end of the central clement being connccti ed to the terminal plate at the corresponding end of the next adiacent element on one side thereof and the terminal plate at the other end of the central element being similarly connected to the terminal plate at the corresponding end of the adjacent section on the 'i op osite side thereof, while thc other termina lates of the outer elements are respective y connected to the circuit-terminal studs N (l for connection with .the line-circuit. The rheostat elements may be supported in any suitable or convenient manner. l have shown a simple and convenient arrangement to which, however, I do not desire to be limited, wherein I ein loy a casing having a flange portion R an a connecting web portion P, the Harige portion R having, if desired, feet S to afford means for supporting or securing such casing. The web rtion l of the casing is provided with ho es therethrough, throu h which extend the threaded ends D ot the rIieostat-element bolts B, nuts 'l serving to clamp the web portion P of the supportin -casing down upon the nut I-I, through w ich the pile of sections composing the element are clamped against the head C of the bolt B.

It is obvious that the elemente composing the rheostat may be supported in many other specifically different ways. Il do not desire, therefore, to be limited or restricted in this respect. It is also obvious that many other variations and changes in the details of construction and arrangement would readily suggest themselves to persons skilled in the art and still fall within the spirit and scope of my invention.

Having now set forth the object and nature of my invention and various constructions embodying the principles thereof, what I claim as new and useful and of my own invention, and desire to secure by Letters Patent, is-

1. A rheostat element coin i sing metallic sections piled upon each ot er to form a space therethrough and therebetween, and means for clamping the pile of sections together.

12. A. rheostat element comprising metallic sect ions piled the one upon the other in crosswise relation to form a central opening or passage therethrough, and a clamp-bolt passing through snid passage or opening for clamping said sections together.

3. A rheostat element comprising wire serm tions piled the one upon the other in crosswise relation, and means for clamping said sections together.

4. A rheostat element comprising sections ot' iron iled the one upon the other in crosswise relation, and a clamp-bolt extendin through the pile and out of contact with sai sections for clam ing said sections together.

5. A rhcostat e ement comprising substantially U shaped metallic sections )iled in crosswisc relation the one upon the otlicr, and means lor clamping said sections together.

I-f 6. Arhcostat element comprisin substantially U-'shaped Wire sections ille in crosswise relation the one upon tlie other, and means for clamping said sections together.

7. A rheostat elementJ comprising sections of wire iled the one upon the other in crosswiserelation to form spaces therebetween, and a clanipflaol-t passino' through such pile and out of contact withtthe sections composing the sonic for clamping said sections together. y

S. A rheostat clement comprising metallic sections piledv cross'wise upon the adjacent sections having a pluralityv of crossingoints, said sections in e ceti-ical contact wit each other at the crossing points thereof, and means for clamping said sections together;

i). A rheostat element comprising metallic sections piled crosswiscopon each other, each metallic section having bearing contact with the nextadjncent section on opposite sides thereof only at the sevral seperated points where sind sections cross each other, and means for clamping said sections together.

\ l0. Arheostatelement con), rising metallic lveti'ons piled in crosswise re ation the one o an the other to form as ace therethrough and therebetween, in combination with terinitial plates associated with such pile, and

means for clam ing said sections and terminal plates toget er. p

11 A rheostat element'eomprising metallic sections circular in cross-section piled the one u )on the other in crosswiserelation, terminal plates arranged at the ends of the pile of sections, and means for clamping said terminal plates and sections together.

12. A rlicostat clement eonnirisingv wire metallic sect-ions piled the one upon the other in crosse-'isc relation, a headed bolt extending through the pile of sections, and a damp nut, mounted on lho end oi said bolt for clamping said sections in assembled relation between said mit sind head.

lil, ,l rheostat clement comprising!` open metallic scc-tions pilcrl in crosswisc relation the one upon the ciber. so as lo form an enlarged open spam at. the middle, a heeded boli extending; through the pile ol assembled sections bm out of contact therewith, a mit mounted upon said bolt for clamping said sections together, :md insulating-washers interposed, rvsporivel5, between tbc pile of sections and ilu lxvml ol' `said bolt and Vsaid mit4 i i4. .i rhvosnl Gleim-nl comprising metallic sections piled the one upon llw other in rrossi wisc relation, :i lwmlwl holt extending; through lln` pilll ol' assembled sei-tions init i out of rentar-t lilou-will, the bully portion ol' said boh living l'rcc from insulation,a not mounted upontlw cnil of said bolt for clampl ing said sections between said nut and the head of said boltand terminal plates interposed, respectively, between said nut and the lead of said bolt and the pile of assembled metallic sections.

l5. A rlicostat element comprising metallic sections piled the one upon tho other in crossrelation, a headed boltv .extending through the pile of assembled sections but out of Contact therewith, the body of the bolt -heing surrounded by an sir s acc, a nut mounted upon the end of said bo t for clam ing said sections between said 'nut and t e head of said' holt, terminal plates interposed, respectively, between said nut and the head of said bolt and the pile of assembled metallic sections and means for insulating said terminal plates from said bolt.

` 16. A rheostat element comprising metallic sections iled the one upon the otherin crosswise re ation, a headed bolt extending throu l1' the ile of assembled sections but out o contact therewith, the body oi the bolt being free from insulating material but su'rrounded by an air-space, e nut mounted upon the end of said bolt for ciampi said sections between said nut and the hea ofrsaid bolt, terminal lates interposed, respective?, betgeen sai nut and the head of said bo t and t e insu ating means for centering seid terminal plates with respect to said bolt.

.17. In arheostat element, a boltthreaded et one end and rovidcd with a head at the other end, meta lic sections strung over said bolt and piled the one u on the other in crosswise relation, snidmeta lic sections each having a plurality of separated points of contact with the adjacent sections and ai nut mounted upon the threaded end of said bolt to clamp or hold the pile of assembled sections between the same and the head of said holt.

i8. ln a rlieostat'element, a bolt threaded at one end and rovid-d with av head at the other end, meta lic sections strung over said bolt and piled the one u on the other in crosswise relation, said meta lic sections each having a plurality of separated points of contact withI the adjacent sections, a nut mounted upon the threaded end ol' said bolt to clamp or hold the pile of assembled srctions between the salu und the head o1' said bolt, and insulating-washers interposed between said nut and bond, respectively, and tho pile of assembled sections.

19. A rheostat comprising one or more clemente, cach element including a bolt, metall lie sections' consisting of wires lient so as to form cach section with :in enlarged central opeoinpr piled the one oport the other in crosswisi relation and supported by said bolt, n su;iportingcasing, and ineens for clamping said holt to said casing,

2U. A rlioostal comprising one or more el?- iucnts, cach clement including a, bolt,'a pi c pile of assembled metallic sections, and

IIC

of metallic sections consisting of wires bent so as to form each section wlth an enlarged central opening superposed in crosswise relation the one upon the other and strung upon said bolt, terminal plates, a supporting-casing, and means for clamping said plates to said casin 21. A r eostat comprising one or more elements, each element including a bolt, a pile of metallic sections superposod in crosswise relation the one upon the other and' strung upon said bolt, terminal plates, a supportl ing-casing, Ineens for clamping said plates to said casing, and circuit-'terminal studs in electrical connection with the terminal lates at o p osite ends, respectively, of ysaid e ements.

n witness whereof I have hereunto set my hand this 2d day of December,"` 1904fin the presence of the subscribing witnesses,

.EDMUND C. MORGAN. 

